Inlayonlay

Inlay-onlay is a term used in dentistry to describe indirect restorations that repair damaged posterior teeth. The term covers both inlays, which fit within the natural margins of the tooth, and onlays, which extend over one or more cusps to protect the chewing surface. These restorations are fabricated outside the mouth, either in a dental laboratory or at chairside using digital scanning and CAD/CAM technology, and then cemented or bonded to the prepared tooth.

Indications for inlay-onlay restorations include moderate tooth structure loss due to caries or fracture when a direct filling is not sufficient but a full crown is not necessary. They are often chosen when preserving healthy tooth structure is important, when esthetics matter, and when a strong, durable restoration is required after endodontic therapy or after extensive decay. They are suitable for teeth with good periodontal support and sufficient enamel for bonding.

Materials used range from gold and other metals to ceramic, porcelain-fused-to-metal, and composite resin. Ceramics and composites are common for esthetic reasons, while gold has long been favored for durability. Fabrication can be done indirectly in a lab or using chairside CAD/CAM systems, with the final restoration cemented or bonded to the tooth using resin-based or glass ionomer cements.

The procedure involves meticulous tooth preparation, accurate margins, and a precise impression or digital scan. After fabrication, the restoration is tried in, adjusted for occlusion, and then permanently seated with appropriate cement. Finishing and polishing complete the restoration.

Advantages include conservation of healthy tooth structure, strong wear resistance, and good esthetics with ceramic materials. Disadvantages can include higher cost, longer treatment times, and greater technique sensitivity compared with direct fillings. Longevity typically ranges from several years to over a decade, depending on material, design, and patient factors.